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United States Patent |
6,254,086
|
Sunou
,   et al.
|
July 3, 2001
|
Sheet accommodating device
Abstract
A sheet accommodating device comprises a first pinion (39a) rotatably
disposed at a center of a table; second, third, fourth, and fifth pinions
(39) which are rotatably disposed on the both sides of the table; a first
regulating member (34) which has rack portions (36, 38) that can be
engaged with the first pinion, second pinion and fourth pinion; a second
regulating member (35) which has rack portions (37, 38) that can be
engaged with the first pinion, third pinion and fifth pinion; and lock
means (33) for positioning any one of the first and second regulating
members.
Inventors:
|
Sunou; Kazuo (Ibaraki, JP);
Shirakawa; Junji (Ibaraki, JP);
Muneyasu; Takayuki (Ibaraki, JP)
|
Assignee:
|
Hitachi Koki Co., Ltd. (Tokyo, JP)
|
Appl. No.:
|
605428 |
Filed:
|
June 29, 2000 |
Foreign Application Priority Data
| Jul 02, 1999[JP] | 11-188319 |
Current U.S. Class: |
271/171 |
Intern'l Class: |
B65H 001/00 |
Field of Search: |
271/171
|
References Cited
U.S. Patent Documents
5215303 | Jun., 1993 | Yamada et al. | 271/171.
|
6089566 | Jul., 2000 | Xu et al. | 271/171.
|
Foreign Patent Documents |
63-258323 | Oct., 1988 | JP | 271/171.
|
5-294471 | Nov., 1993 | JP | 271/171.
|
Primary Examiner: Bollinger; David H.
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak & Seas, PLLC
Claims
What is claimed is:
1. A sheet accommodating device comprising:
a table on which a sheet is stacked;
a first pinion rotatably disposed at a center of the table;
a second pinion rotatably disposed on one end side of the table;
a third pinion rotatably disposed on the other end side of the table;
a fourth pinion connected to the second pinion and arranged above the
second pinion;
a fifth pinion connected to the third pinion and arranged above the third
pinion;
a first regulating member disposed on one side of the table, the first
regulating member having a first rack portion projecting inside the first
regulating member and engagable with the first pinion;
a second regulating member facing the first regulating member, the second
regulating member having a second rack portion engagable with the first
pinion; and
a lock for positioning any one of the first and second regulating members.
2. The sheet accommodating device as claimed in claim 1, wherein the lock
comprises a positioning plate having a groove, any one of the first and
second regulating members has a lock pin to be engaged with the groove of
the positioning plate, and the lock pin prevents the one of the first and
second regulating means from moving except for a predetermined direction.
3. The sheet accommodating device as claimed in claim 2, wherein the lock
comprises a coil spring for engaging the lock pin with the groove of the
positioning plate.
4. The sheet accommodating device as claimed in claim 2, wherein the lock
comprises a release lever for releasing the engagement of the lock pin
with the groove of the positioning plate.
5. The sheet accommodating device as claimed in claim 1, wherein the second
regulating member is engagable with the first pinion through the second
rack portion projecting inside the second regulating member.
6. A sheet accommodating device comprising:
a table on which a sheet is stacked;
a first pinion rotatably disposed within a central portion of the table;
a second pinion rotatably disposed on one end side of the table;
a third pinion rotatably disposed on the other end side of the table;
a fourth pinion connected to the second pinion and arranged above the
second pinion;
a fifth pinion connected to the third pinion and arranged above the third
pinion;
a first regulating member disposed on one side of the table, the first
regulating member having a first rack portion projecting inside the first
regulating member and engagable with the first pinion; and
a second regulating member facing the first regulating member, the second
regulating member having a second rack portion engagable with the first
pinion.
7. The sheet accommodating device as claimed in claim 6, wherein the second
regulating member is engagable with the first pinion through the second
rack portion projecting inside the second regulating member.
8. The sheet accommodating device as claimed in claim 7, wherein the fourth
pinion is connected to the second pinion by a shaft so as to rotate with
the second pinion.
9. The sheet accommodating device as claimed in claim 8, wherein the fifth
pinion is connected to the third pinion by a shaft so as to rotate with
the third pinion.
10. The sheet accommodating device as claimed in claim 8, further
comprising a lock for locking in a position one of the first and second
regulating members.
11. The sheet accommodating device as claimed in claim 6, wherein the first
regulating member further comprises a third rack portion projecting
outside the first regulating member and engaged with the fourth pinion.
12. The sheet accommodating device as claimed in claim 11, wherein the
second regulating member further comprises a fourth rack portion
projecting outside the second regulating member and engaged with the fifth
pinion.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sheet accommodating device which is
applied to a paper supplying section or a paper exhausting section of an
image forming apparatus such as a laser printer, a copier, or the like.
2. Description of the Related Art
A sheet accommodating device applied to an image forming apparatus can be
broadly classified into a small-sized type in which the sheet capacity is
about 250 to 500 sheets, and a large-sized type in which the sheet
capacity is about several thousands sheets.
Recently, a sheet accommodating device has been widely used, in which a
regulating member for regulating a sheet position is provided so that the
regulating member can be moved according to a size of a sheet to be used
and so that it can correspond various sizes of sheets.
In case of the large-sized type of the sheet accommodating device, the
corresponding depth is required. Therefore, the large-sized type of sheet
accommodating device must be equipped with a regulating member having
several times as large as a regulating member in the small-sized type of
sheet accommodating device has. Since the regulating member of the
large-sized type of the sheet accommodating device is generally formed as
a sheet metal member or a thin plastic product, it cannot help being made
of flexible material.
In case that the position of the regulating member having such the large
size is changed according to the size of a sheet, conventionally, the
regulating member is detached at every change, then reattached to the size
position of the sheet to be used and fixed there. Therefore, the
regulating member of the large size is troublesome in that it is inserted
into slits provided at each size of the sheets to be fixed and that it is
fixed by a fixing member such as a screw, a magnets or the like.
SUMMARY OF THE INVENTION
An object of the invention is to provide a sheet accommodating device which
is superior in operationality and also can position the regulating member
accurately.
In order to achieve the above object, a sheet accommodating device
comprises a table on which sheets are stacked; a first pinion rotatably
disposed at a center of the table; a second pinion rotatably disposed on
one end side of the table; a third pinion rotatably disposed on the other
end side of the table; a fourth pinion that is connected to the second
pinion and arranged above the second pinion; a fifth pinion that is
connected to the third pinion and arranged above the third pinion; a first
regulating member which is arranged on one side of the table and has rack
portions that can be engaged with the first pinion, second pinion and
fourth pinion; a second regulating member which is arranged so as to be
opposite to the first regulating member and has rack portions that can be
engaged with the first pinion, third pinion and fifth pinion; and lock
means for positioning any one of the first and second regulating members.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a whole constitutional view of a laser printer in which a sheet
accommodating device of the invention is mounted.
FIG. 2 is a schematic perspective view showing one embodiment of the sheet
accommodating device of the invention.
FIG. 3 is a constitutional view showing a slide mechanism of a regulating
member in the sheet accommodating device of the invention.
FIG. 4 is a constitutional view showing a lock mechanism of the regulating
member in the sheet accommodating device of the invention.
FIG. 5 is a constitutional view showing another embodiment of the lock
mechanism.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
An embodiment of a sheet accommodating device according to the invention
will be described below in detail with reference to drawings.
FIG. 1 is a whole constitutional view of a laser printer in which a sheet
accommodating device of the invention is applied to a paper supplying
section. In FIG. 1, reference numerals 1, 2 and 3 are sheet accommodating
devices, of which the sheet accommodating device 3 has a larger sheet
capacity than the other sheet accommodating devices 1 and 2 and can supply
a large amount of sheets to the laser printer. The sheet accommodating
devices 1, 2 and 3 can be drawn out in the direction perpendicular to a
sheet surface of FIG. 1. When the sheet accommodating devices are put into
their predetermined attaching positions and mounted in a main body of the
printer, optical sensors (not shown) detect the mounting of each sheet
supplying device and then the sheet supplying devices engage with elevator
table driving gears (not shown), so that elevator tables are raised till
the top surfaces of sheets stacked on the elevator tables (the upper
surfaces of the elevator tables in case that there are no sheets on the
elevator tables) come into contact with the paper feed rollers 20, 21 and
22.
Reference numeral 4 represents a photosensitive drum, which starts rotating
in accordance with signals from a controller (not shown). As the
photosensitive drum 4 starts rotating, a surface of the photosensitive
drum 4 is uniformly charged by a corona charger (not shown). On the
charged photosensitive drum 4, an electrostatic latent image is formed by
an optical system (not shown). When the electrostatic latent image reaches
a position of a developing device (not shown), it is developed by toner
and made visible on the photosensitive drum 2 as a toner image. The toner
image thus formed by the known electrophotographic process is transferred
onto the sheet fed out from a sheet tray 1, 2 or 3 by a transfer unit 5.
Reference numeral 6 is a fixing device, by which the toner image
transferred on the sheet is fixed. Reference numeral 12 is a gate member
for switching directions of sheets to be transported, and 11 is a paper
exhausting tray on which sheets on which images have already been formed
are stacked.
Reference numeral 14 is a paper feeding passage communicating with paper
supplying sections 1, 2 and 3; image forming means 4, 5, and 6; and the
paper exhausting tray 11. Reference numeral 13 is a paper drawn-in
passage, which diverges from the paper feeding passage 14 downstream in
the paper transporting direction with respect to the image forming means
4, 5 and 6, and selectively draws the sheet fed out from the fixing device
6 therein by switching of the gate member 12. Reference numeral 15 is a
return passage which diverges from the paper drawn-in passage 13, and of
which an end joins the paper feeding passage 14 upstream in the paper
transporting direction with respect to the image forming means 4, 5 and 6.
Accordingly, in case that printing is performed on both sides of the sheet,
the sheet fed out from the fixing device 6 is drawn in the paper drawn-in
passage 13 and then this sheet is fed out to the return passage 15,
whereby the sheet on which recording has been performed on one side is
again fed out to the image forming means, so that two-sided recording is
executed. In FIG. 1, reference numerals 7 and 8 are feed rollers provided
before and after the gate member 12; 9 and 10 are feed rollers, in which
forward rotation and backward rotation can be switched, and their rollers
9 and 10 are provided on the paper drawn-in passage 13; and 16 is a gate
member for guiding the sheet drawn in the drawn-in passage 13 to the
return passage 15 or guiding the sheet drawn in the drawn-in passage 13
again to the paper feeding passage 14.
Next, the constitution of the sheet accommodating device will be described
with reference to FIGS. 2, 3 and 4. FIG. 2 is a schematic perspective view
of the sheet accommodating device 3, FIG. 3 is a detail view of a slide
mechanism of the regulating member, and FIG. 4 is an enlarged detail view
of a lock mechanism of the regulating member.
In FIG. 2, reference numeral 3 represents a sheet accommodating device; 30
represents a table on which sheets are stacked; 31 represents a drive
shaft attached to the sheet accommodating device; 31a represents a
transmission gear that is engaged with an elevator table driving gear (not
shown) disposed on the main body and transmits power to the drive shaft
31; 31b and 31c represent wire drums for winding up wires that hang down
the table 30; 32a, 32b, 32c and 32d represent wires that hang down the
table 30; and 33 represents a release lever for releasing lock of the
regulating members 34 and 35.
Next, the slide mechanism of the regulating members 34 and 35 will be
described with reference to FIG. 3. To the lower portion of each of the
regulating members 34 and 35, racks 36 and 37 are attached, and to the
upper portion thereof, a rack 38 is attached. In the racks 36 and 37, the
rack portions which project outside the regulating members 34 and 35 are
engaged with pinions 39 rotatably supported by the sheet accommodating
device 3, while rack portions which project inside the regulating members
34 and 35 are engaged with a pinion 39a rotatably supported at the center
of the sheet accommodating device 3 in such a manner that the rack
portions use the pinion 39a in common. Further, in the racks 36 and 37,
pinion shafts 40 are coupled to the upper portions of the pinions 39, and
a pinions 39 disposed at the upper ends of the pinion shafts 40 are
engaged with the racks 38 provided at the upper portions of the regulating
members 34 and 35.
The racks 36 and 37 are regulated in the sliding directions by guide pins
41 fixed to the sheet accommodating device 3 and can be slid only in the
direction B of FIG. 2. Guide shafts 42 provided at the upper portions of
the regulating members 34 and 35 are inserted into support members 43
fixed to the sheet accommodating device 3, and can be slid only in the
direction B of FIG. 2.
As described above, the regulating members 34 and 35 of the large size are
slidably supported by the racks and the pinions in the upper portions and
the lower portions thereof. Therefore, flexure is suppressed and the
regulating members 34 and 35 are held firmly. Further, by sliding the
release lever 33 in the direction A to release the lock, the regulating
member 34 can be slid in the direction B of FIG. 2, so that the regulating
member 35 is slid in accordance with the sliding movement of the
regulating member 34.
Next, the lock mechanism of the regulating members 34 and 35 will be
described with reference to FIG. 4. Grooves engaged with a lock pin 50
fixed to the regulating member 34 are formed in positioning plates 52 and
53. Here, the grooves are formed respectively in the positioning plates 52
and 53 at the different position from each other. The two positioning
plates are used in piles, whereby it is possible to finely set the lock
position at a narrower pitch than the outer diameter of the lock pin 50.
Further, the number of the positioning plates is not limited to two, and
increase of the number of the positioning plates can cause increase of the
lock position. The positioning plates 52 and 53 are regulated in the
sliding direction thereof by a guide pin 51 fixed to the regulating member
34, and they are attached so that they can be slid only in the directions
A and C of FIG. 2.
Further, a tension coil springs 54 are respectively attached to the
positioning plates 52 and 53, and they give urging force by which the
grooves of the positioning plates 52 and 53 are engaged with the lock pin
50. The release lever 33 is regulated in the sliding direction thereof by
a guide pin 55 attached to the regulating member 34, and attached so that
it can be slid only in the directions A and C of FIG. 2. A release lever
rib 33a attached to the release lever 33 is engaged with the positioning
plates 52 and 53 and moves in accordance with the slide of the release
lever 33 so that it slides the positioning plates 52 and 53 in the
directions A and C of FIG. 2, whereby engagement and disengagement between
the grooves of the positioning plates 52, 53 and the lock pin 50 are
performed.
In this connection, the lock mechanism can have various designs other than
the design shown in FIG. 4. For example, as shown in FIG. 5, a release
lever 61 is provided for the regulating member 34 and rotated by a tension
coil spring 63 in the direction E of FIG. 5 round a support pin 62, and a
groove formed in the release lever 61 is engaged with a groove forming
member 60 attached to the sheet accommodating device 3, whereby the
regulating member 34 may be fixed. By rotating the release lever 61 in the
direction D of FIG. 5, the engagement between the release lever 61 and the
groove forming member 60 is released, so that the regulating member 34 can
be moved in the direction B of FIG. 2.
As described above, according to the invention, it is possible to provide a
sheet accommodating device which is superior in operationality and also
can position the regulating member accurately.
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